U.S. lawmakers will step up efforts this week to put more pressure on North Korea through legislation calling for the repatriation of Korean War prisoners and toughening sanctions for its alleged proliferation activities, congressional officials said Sunday.

On Tuesday, the U.S. House of Representatives will put to a floor vote a resolution calling for the release of American and South Korean prisoners of war (POWs) and civilian abductees still in North Korea after the 1950-53 conflict.

The House Subcommittee on Asia and the Pacific unanimously approved the resolution late last month. Amid bipartisan support, House leaders decided to put the resolution to a floor vote without a markup in the Committee on Foreign Affairs, added the officials.

The entire House also plans to vote on a bill imposing tougher sanctions against North Korea, Iran and Syria, which are all accused of being involved in the proliferation of weapons of mass destruction.

The Iran, North Korea, and Syria Nonproliferation Reform and Modernization Act will amend the existing Iran, North Korea, and Syria Nonproliferation Act by expanding the range of proliferation sanctions and the activities subject to sanctions.

The bill, sponsored by Rep. Ileana Ros-Lehtinen (R-FL), who chairs the House Foreign Affairs Committee, also expands sanctions applicable to certain foreigners and places restrictions on nuclear cooperation with countries aiding proliferation by the three states.

Ros-Lehtinen's office confirmed that the bill will be discussed on the House floor this week, but it did not specify the date. (Washington=Yonhap)